Historically, throttle control on a motorcycle has been a mechanical gas control in which the gas handgrip is connected to the intake system by a cable. Cable control makes it possible to have feedback regarding the degree of opening of the intake system (generally a butterfly valve or a slide valve) because of the return force of the return spring of said system.
Motorcycles fitted with electronic throttle control (ETC) systems, also known as “ride-by-wire” or electronic control systems, comprise a throttle handgrip connected to a position sensor.
In such a system, the handgrip no longer drives a cable connected to the intake system as it did in fully mechanical control systems, in which the return force varied with the torque demanded.
In the absence of feedback, it is difficult for the user to meet the request for torque, which may vary widely from one riding style to another.
For example, the stiffness of the handgrip is dependent on the tension of an internal spring and is fixed after design or adjustment.
Depending on the stiffness chosen, the use of the handgrip may be difficult or even uncomfortable, or may be too slack.
The following documents are known from the prior art.
Document DE 102013213050, incorporated herein by reference, discloses an active system the force feedback from the accelerator pedal of which is dependent on the pressure applied by the driver to the pedal and on the angle by which this pedal is depressed, for controlling speed or distance in traffic.
Document DE 102011055482, incorporated herein by reference, discloses an accelerator pedal for a hybrid vehicle which changes state according to whether it is the electrical or the combustion engine system that is providing the drive, giving the driver a different feel when depressing the pedal according to whether it is the combustion engine that is active or the electric motor that is active, so that the driver can easily recognise which form of drive is active.
Document US 20110260557, incorporated herein by reference, discloses an actuator arranged in parallel with the accelerator pedal return spring and which alters the resistance of the pedal when switching from combustion-engine drive to electric-motor drive and vice versa.
Document IN2003MU01102 (equivalent to FR 3063043), incorporated herein by reference, relates to a system for perceiving the opening of a gas butterfly valve on a vehicle fitted with a handlebar and with a throttle handgrip. The handgrip comprises a cam which offers a point of increased resistance to rotation of the handgrip upwards of a certain demanded power corresponding to an economical mode. This increased resistance is achieved by means of a cam that has to be overcome when leaving the economical mode to enter a power mode.
These documents thus disclose devices that enable the driver to be alerted to a change in driving/riding mode, for example a change between combustion-engine and electric modes in the case of hybrid vehicles or between economical and power modes on a combustion engine.